DELTA, Utah -- A 9-year-old girl was killed and two other schoolchildren were critically injured Thursday afternoon when a snowplow crashed into a school bus during a snowstorm. The snowplow apparently lost control while traveling on a state highway at 3:30 p.m. Its blade split open the side of the school bus, which was carrying at least 20 children. Camille Kunzler, 9, suffered severe head injuries and died a short time later at a local hospital. Two other children, ages 8 and 13, suffered critical head injuries. The Salt Lake Tribune reported that several other students were recovering from an assortment of injuries, from cuts to broken bones. The bus driver suffered broken bones and cuts, while the snowplow driver sustained cuts to his face and head. The newspaper reported that blizzard-like conditions, combined with high winds, grounded a rescue helicopter, which had been requested by emergency workers.